The big thing to remember is that the editor is trying to help YOU make the novel better, not make the novel their own vision. So take the suggestions they gave you and figure how to make those changes (if you agree with them) in a way that fits your vision. That's what I do. And occasionally there's something that they want that I can't figure out how to change and make it my story, and so I don't change it. I haven't had a problem with those things I refused to change with my editor yet.